The Sanje mangabey (Cercocebus sanjei) is a highly endangered Old World monkey of the white-eyelid mangabey group from Tanzania.[1] They are about 50–65 centimeters long, excluding tail, and weigh about 7–9 kilograms,[3] and their body color is greyish. They live in valley forests, but are mostly ground-dwelling,[4] which makes them susceptible to hunting and poaching. Fruit makes up about 70% of their diet, while foliage makes up most of the rest.[3]